1. Field of the Invention
This invention relates to high density storage systems for records, books, files, parts and the like and more particularly to an improved movable aisle storage system.
2. Description of the Prior Art
Because of high rent costs and other factors, there is a great demand for high density storage systems which offer maximum storage space and require only a minimum floor area. When storage equipment, such as shelves, bins and cabinets, for example, are arranged in rows sufficient aisle space must be provided between adjacent rows to permit access to the stored material. Since most of the aisle space is not in use at a given time, movable aisle storage systems have been developed which provide aisle space between adjacent rows of storage equipment only when that space is actually needed thereby substantially reducing the overall floor area required for the system. To accomplish this, a row of storage equipment, such as the aforementioned shelves, bins, etc. is mounted on a movable carrier having wheels which engage a set of rails which are mounted in a track and deck assembly. The system is so arranged that all of the rows of storage equipment on the movable carriers except one are stacked together so that only a single aisle is provided between the stacked rows and the remaining row. By rolling the appropriate carriers, an aisle may be created between those rows of storage equipment to which access is desired.
The problems encountered by presently known movable aisle storage systems are many and varied. For example, the known systems must usually be installed by skilled workmen especially when the floor on which the track and deck assembly is located is not perfectly level or where sections of rail must be joined together to form a long track length for the movable carriers. Additionally, many of the known systems could damage the floor of the building in which the system is installed because grouting or shimming of the rails is required or because the track and deck levelling adjustment screws bear against the floor or because the track and decking must be fastened directly to the building floor. Further, since all floors except concrete slab floors settle and since the loading of the storage equipment may change, the problem of levelling the rails and deck panels after installation and loading of the system arises. In many of the known arrangements, this is difficult if not impossible without unloading and disassembling the system.
With respect to the safety of the employees who must use the system, the rails should be recessed in the track and deck assembly to prevent tripping, deck panels should be adequately supported to prevent bouncing when walked upon and an easily installed anti-tip means be provided to prevent the rows of storage equipment from being accidentally tipped over. Furthermore, many of the known systems require substantial maintenance because of the need to remove debris which accumulates between the rails and the deck panels which form the track and deck assembly. This problem arises because many of the known systems utilize laterally-extending guides which bear against the rails adjacent the carrier wheels to prevent "yawing" of the movable carriers, so that a substantial space is created between each rail and the adjacent deck panels. Finally, it is often difficult to install optional equipment, such as mechanicl drive systems, for example, in the known systems after the initial installation has been completed.